Scientists went to the Krubera Cave, the deepest known cave on the planet,
to discover the world's deepest insects. They found these creepy-crawlies
living more than 6,400 feet below the Earth's surface:

Researchers documenting life in the world’s deepest cave,
Krubera-Voronya on the eastern side of the Black Sea, discovered four
new species of springtail, including the eyeless Anurida stereoodorata
(inset), which subsist on fungi and decaying organic material. The intrepid
scientists monitored sections of the cave for a month, looking for life
using pitfall traps baited with cheese. Two of the species, Plutomurus
ortobalaganensis (pictured above), found 1980 meters down, and Schaefferia
profundissima found 1600 meters down, now hold the record for deepest
living underground invertebrates, researchers report today in Terrestrial
Arthropod Reviews.